The fields of life science research and pharmaceutical development are dependent upon highly selective and sensitive quantitative assays for a wide range of different biomolecules (such as proteins, antibodies, cytokines, receptors, enzymes, peptides, nucleic acids, hormones, and the like) in complex clinical or biological samples (such as blood, urine, tissue or cellular extracts, cell culture supernatants, bioprocess feedstreams, and the like). In typical samples (which may contain thousands of different molecular species) the analytes of interest may be present at extremely low concentrations (nanograms per milliliter or less), but the samples may be available only in very small quantities (microliters or less). The rapid growth in the field of biotechnology and the introduction of many potential new drug targets from genomic research have created an increasing demand for more rapid and efficient analytical methods, without any sacrifice in performance.
In order to simultaneously obtain high selectivity (the ability to measure one very specific molecule in a complex mixture) and high sensitivity (the ability to accurately quantify very small concentrations or amounts), a number of analytical methods have been developed which couple powerful molecular separations with extremely responsive detection methods.
Existing methods, such as ELISA assays suffer from insufficient sensitivity and specificity and are expensive. New methods are needed for diagnostic assays to allow for sensitive and specific detection of analytes.